Thats something Intel would be quite envious of.
Rewiring address lines likely did not allow for a working EPROM due to where the defect was, thus cutting the word size down. Initially, it was thought that the EPROM would be too expensive for mass production use and that it would be confined to development only. There are other benefits typically speed increases and power decreases aside from leakage but from a purely economical stand point, the smaller dies result in more profits. An insulating layer of oxide is grown over the channel, then a conductive silicon or aluminum gate electrode is deposited, and a further thick layer of oxide is deposited over the gate electrode. Sorry, your blog cannot share posts by email. Please write us about any error, missing part or comments! As you can see that while they are all the same part, the dies are significantly different. One has bonding wires on all 4 sides, while the second one has bonding wires only on the top and bottom of the die, and a completely different layout to the die. As the quartz window is expensive to make, OTP one-time programmable chips were introduced here, the die is mounted in an opaque package so it cannot be erased after programming - this also eliminates the need to test the erase function, further reducing cost. So, the pin 22that in the is the 9th address line, in the is a ground. This certainly was not an uncommon procedure, even Intel regularly sold EPROMs as swhether to use a die with an imperfection, or to simply meet demand. They result in smaller die sizes for the same part, which results in more chips per wafer, thus increasing revenue. The floating-gate electrode has no connections to other parts of the integrated circuit and is completely insulated by the surrounding layers of oxide. Even dust inside the package can prevent some cells from being erased.
#2708 eprom programmer manual
However, as this was not universal, programmer software also would allow manual setting of the manufacturer and device type of the chip to ensure proper programming. The process takes several minutes for UV lamps of convenient sizes sunlight would erase a chip in weeks, and indoor fluorescent lighting over several years. You may also view them in raw directory form here and a few that didnt make it into the gallery here. Paper data storage Drum memory Magnetic-core memory Plated wire memory Core rope memory s Thin-film memory Disk pack Twistor memory - Bubble memory - Floppy disk By using this site, you agree to the Terms of Use and Privacy Policy. The erasing window must be kept covered with an opaque label to prevent accidental erasure by the UV found in sunlight or camera flashes. To read a eprom we need 10 output for the address bus, and 8 input for the data bus: The data sheet lists pin 19 as Eeprlm R Address reference and specifies it to be driven low, or for the S driven high. \ddressable by DIP swi tch to any 14K or br. Add 2K of firmware using a handful of components that fit right on the D2 board. A Simple EPROM Programmer for the Motorola D2 Kit.